JavaScript Cookbook

Colophon

The animal on the cover of JavaScript Cookbook is a little (or lesser) egret (Egretta garzetta). A small white heron, it is the old world counterpart to the very similar new world snowy egret. It is the smallest and most common egret in Singapore, and its original breeding distribution included the large inland and coastal wetlands in warm temperate parts of Europe, Asia, Africa, Taiwan, and Australia. In warmer locations, most birds are permanent residents; northern populations, including many European birds, migrate to Africa and southern Asia. They may also wander north after the breeding season, which presumably has led to this egret’s range expansion.

The adult Little Egret is 55–65 cm long with an 88–106 cm wingspan. It weighs 350–550 grams. Its plumage is all white. It has long black legs with yellow feet and a slim black bill. In the breeding season, the adult has two long nape plumes and gauzy plumes on the back and breast, and the bare skin between its bill and eyes becomes red or blue. Juvenile egrets are similar to nonbreeding adults but have duller legs and feet. Little egrets are the liveliest hunters among herons and egrets, with a wide variety of techniques: they may patiently stalk prey in shallow waters; stand on one leg and stir the mud with the other to scare up prey; or, better yet, stand on one leg and wave the other bright yellow foot over the water’s surface to lure aquatic prey into range. The birds are mostly silent, but make various croaking and bubbling calls at their breeding colonies and produce a harsh alarm call when disturbed.

The little egret nests in colonies, often with other wading birds, usually on platforms of sticks in trees or shrubs, in reed beds, or in bamboo groves. In some locations, such as the Cape Verde Islands, the species nests on cliffs. In pairs they will defend a small breeding territory. Both parents will incubate their 3–5 eggs for 21–25 days until hatching. The eggs are oval in shape and have a pale, nonglossy, blue-green color. The young birds are covered in white down feathers, are cared for by both parents, and fledge after 40 to 45 days. During this stage, the young egret stalks its prey in shallow water, often running with raised wings or shuffling its feet. It may also stand still and wait to ambush prey. It eats fish, insects, amphibians, crustaceans, and reptiles.

The cover image is from Cassell’s Natural History. The cover font is Adobe ITC Garamond. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont’s TheSansMonoCondensed.